The daily course of wind speed and direction over chosen active surfaces close to the sea shore
on the Łeba Bar have been analysed. Measurements took place in the vicinity of the field station of the
Department of Climatology, Adam Mickiewicz University in the period from the 1st of July until 25th of
August 2009. Two measurement posts, representing different morphological and plant zones were chosen:
1) the frontal dune, 2) coniferous forest, and additionally, the measurements from an automatic meteorological
station, located at the grey dune in the topographic low behind the frontal dune, were used.
The daily cycle of wind speed changes, with its maximum in the early afternoon and minimum at night,
was identified at both measurement posts. Wind speed decreases towards the land interior. The difference of
a few hundred meters distance from the sea shore between posts 1 and 2 causes substantial decrease in wind
speed. Additionally, the topography of the second post, which is located in the forest, in the depression behind
the frontal dune, strongly reduces wind speed.
The breeze circulation was weak during the measurement period while the macroscale western circulation
was dominant with shorter periods when the eastern flow dominated. The effect of the night breeze was
expressed by southern deviation of wind direction and the daily breeze in the afternoon, whereas in the evening
the northern directions dominated.